Wheel chock

ABSTRACT

There is disclosed an improved wheel chock in the form of a hollow wedge with a ribbed inclined tire gripping face and a base which is concave upwardly to form ground gripping rails whose contact area with the ground varies with the loading of the wedge.

United States Patent Vick I 1 Apr. 2, 1974 1 1 WHEEL CHOCK [76]Inventor: Merlin E. Vick, 4708 Salem Dr.,

Mesquite, Tex. 75149 [22] Filed: Aug. 28, 1972 121] App]. No.: 284,338

6/1930 Nicholls 188/32 3,297,111 1/1967 Lisbon 188/32 FQRHIGN PATENTS()R APPLICATIONS 320,897 12/1902 France 188/32 310,185 4/1929 I (ircalBritain 188/32 Primary Examiner-DuaneA. Rcger Attorney, Agent, orFirm-Clcgg and Cantrell [57] ABSTRACT There is disclosed an improvedwheel chock in the form of a hollow wedge with a ribbed inclined tiregripping face and a base which is concave upwardly to form groundgripping rails whose contact area with the ground varies with theloading of the wedge.

2 Claims,- 4 Drawing Figures |2- A 2 13M II III! WHEEL CHOCKBACKGROUND'OF THE INVENTION This invention relates to wheel chocks forpneumatic tired vehicles. It is particularly concerned with a wheelchock of improved compactness and lightness, and one with increasedsafety and reliability as compared to wheel chocks of the kind employedin the past.

It is necessary or desirable to block the wheels of pneumatic tiredvehicles under many circumstances. In the trucking field, trucks,trailers and tractors are normally chocked at depots, and on roadshoulders during emergency situations, to prevent runaway of thevehicle. Aircraft are normally chocked when parked on airport aprons,and during run-up or warm-up of their engines. Even small vehicles suchas automobiles or hand trucks are often chocked to prevent undesiredrolling when the vehicle is unattended or being serviced.

Field expedients are widely employed for chocking purposes. Use is madeofcasually found pieces of lumber or masonry. Occasionally lumber is cutto a general wedge shape to serve as chocks. The holding power andreliability of such field expedients is very problematical. Speciallydesigned chocks have been employed, especially in the trucking andaircraft fields, but these have been of less than satisfactory holdingpower and are relatively heavy and clumsy in use. The design of suchspecially constructed chocks has been such that the dimensions of thechock must be closely correlated with the size of the tire with which itis to be used, and

as a consequence several different sizes of a given chock design must bemanufactured and inventoried in order to market that chock for afullrange of tire sizes.

Such specifically constructed chocks are commonly SUMMARY OF THEINVENTION In accordance with the present invention an improved wheelchock is provided which is compact, lightweight, and convenient .to use.It is so configured and proportioned that its holding power isexcellent, and one size of chock is suitable for use with substantiallythe full range of commonly encountered pneumatic tires, from small handtruck tires to large aircraft tires of the kind used on jet transports.The improved wheel chock of the present invention is a one piece, hollowwedge, preferably cast of a non-sparking metal such as aluminum, whichwedge is generally right triangular in profile, and is provided withtire gripping ribs on its hypotenuse or tire gripping face, as well asroad gripping rails on the base of the wedge. The rails runlongitudinally on the base along its outer edges, and the base isslightly concave upwardly in shape so that the road gripping rails havea limited area of contact with the road, thus assuring high grippingpressure between the wedge and the road. This construction insures thatthe road gripping area will be small, and hence the pressure will behigh, when the chock is lightly loaded, and that the road gripping areawill increase somewhat up to a limit as the loading on the wedge isincreased. The tire gripping ribs on the tire engaging face of the wheelchock are shaped and positioned so that the force applied by a tire tothe chock tends to hold the chock in rolling-blocking position moresecurely. This arrangement serves to increase the holding power of thechock and its reliability.

From the foregoing, it can be seen that it is an object of the presentinvention to provide an improved wheel chock for pneumatic tire vehiclesof increased holding power, safety, reliability and convenience.

The foregoing object, together with other objects and purposes, can bebetter understood by consideration of the detailed description whichfollows, together with the accompanying drawings.

DESCRIPTION OF THE DRAWINGS FIG. 1 is an isometric view of an improvedwheel chock in accordance with the present invention;

FIG. 2 is a rear elevational view of the wheel chock of FIG. 1;

FIG. 3 is a sectionalelevational view of the wheel chock shown in FIG.2, the section being taken along the line 3-3 of FIG. 2; and

FIG. 4 is a bottom view of the wheel chock of FIGS. 2 and 3.

DESCRIPTION OF THE PREFERRED EMBODIMENT The improved wheel chock of thepresent invention is designated generally as 10 in FIG. 1. From FIG. 1it can be seen that chock 10 is a wedge which is generally righttriangular in profile. The wedge 10 has an inclined tire engaging face11, and side walls 12. As shown best in FIGS. 2 and 3, it has an uprightback wall 13, and as appears in FIGS. 3 and 4, a base 14.

In its most preferred form the wedge 10 is generally right triangular inprofile, and is a triangle of the 3-4-5 type. As a consequence, theangle between tire engaging face 11 and base 14 (indicated as angle A)is about 36.9, while angle B between back wall 13 and base 14 is a rightangle and angle C between tire gripping face 11 and back wall 13 isabout 53. 1. It is preferred that the angle A be between about 30 andabout 40. It is also preferred that the dimensions of the wedge be about6 inches X8 inches XlO inches. I have found that with the wedgeproportioned and dimensioned as just described, it has excellent holdingpower for substantially all of the commonly encountered sizes of tires,from the small pneumatic tires employed on wheelbarrows, hand trucks andvery light aircraft, up through and including the large tires employedon tractor trailers, and large transport aircraft. When the angle A issmaller than just'described, the pneumatic tires can too readily roll upand over the inclined face 11 unless the wedge is made inordinatelylong. On the other hand, if the angle A is greater than that justdescribed, the pneumatic tires tend to more readily push the wedge alongthe ground,

Tire engaging face 11 is provided with a plurality of tire gripping ribs15, which, in a chock of the dimensions given in the discussion above,preferably extend above the surface of face 11 about one-fourth inch andare provided in the number of about 17, the spacing being about one-halfinch. Ribs 15 extend laterally across face 11 and have an angularity ofabout It is preferred that the upper faces 16 of the ribs be angledslightly downwardly toward the back wall 15 of the wedge so that whenthe surface of a tire is in engagement with a rib 15 it applies acomponent of force downwardly and somewhat to the right as FIG. 3 isdrawn. This force component tends to seat the 3 wedge against the tirein blocking position. It is preferred that the ribs be so distributed onface 11 that even a small tire will engage one or more of them readily.For this reason at least some of the ribs should be located near thefoot of inclined face 11.

As can best be seen in FIG. 2, the base 14 is slightly concave upwardlywhen viewed from the back of the wedge. The term concave is used hereinin a broad descriptive sense, because convenience in manufacturing makesit desirable that the bottom surface actually be formed of two planarsections which form a very small angle with each other, rather than atrue curved surface the term concave in a more limited sense mightconnote. Base 14 is also provided with an opening 17 therein. Opening 17extends longitudinally over the base as can best be seen in FIG. 4. Thisconstruction, together with the concave shape of the base, results inthe formation of two rails indicated at 18 and 19 on FIG. 4 for grippingthe ground. The rails extend longitudinally over the base and are ofvariable ground gripping area. I I

When a pneumatic tire is lightly loading the wedge 10, only the outeredges ofrails 18 and 19 are in contactwith the ground or road surface.The area of contact is very small, and the contact pressure iscorrespondingly very high, resulting in a good gripping action. As theloading by the tire on the wedge increases, the wedge will tend to beforced into the ground or road surface farther. andmore of the area ofrails 18 and 1.9 will contact the ground or road surface. Such increasedarea will tend to reduce the contact pressure somewhat, which, in turnreduces the danger that the .road surface will be unduly damaged. Astheloading on the wedge by a tire is still further increased,substantially all of the surface of rails 18 and 19, and theintermediate areas of the surface of the base at each end of opening 17will also come into contact with the ground or road'surface. At suchpoint, the area available for i distribution of the load on the groundis exhausted, and further increases in loading by a tire result inincreased gripping pressure between the base and the road/It can beseen, therefore, that in accordance with the present invention,excellent road gripping qualities are pro vided throughout the range ofloading of the wedge, particularly in the light loading end of therange.

The triangular structure of the chock of the present invention isinherently strong. As was pointed out above, it is preferred that thewedge be hollow in order to save on construction materials and onweight. In order to enhance the strength of the wedge notwithstandingits hollow construction, a rib 20 is formed in the interior of thewedge. Rib 20 runs between tire engaging face 11' and back wall 13. Itis so positioned that itintercepts back wall 13 near the bottom thereofand the tire engaging face 11 at a point near the middle thereof. Rib 20thus protects the wedge 10 against crushing under extremely heavy loads.An'aluminum chock having the preferred dimensions discussed above has,under test conditions, withstood a loading of some 26 tons withoutdamage and has withstood a loading of 30 tons (the maximum which thetest equipment could develop) without being broken into pieces orcrushed so that it was inoperative.

As has been mentioned, the preferred material of construction for thewedge is cast aluminum which will not spark when struck or draggedagainst the road or vehicle. Wedge 10 can conveniently be case in onepiece, and the absence of mechanical fastenings which can break orloosen increases the reliability of the device. Side walls 12 areprovided with a hole or opening 21 through which chains may be threadedfor carrying the wedge or through which a hook may be engaged for thesame purpose. In addition hole 21 is of convenience to the user when heis positioning or removing the chock.

From the foregoing it can be seen that in accordance with the presentinvention, an improved wheel chock of superior performance is provided.

What is claimed is:

l. A wheel chock for pneumatic-tired vehicles comprising:

a-hollow wedge having a base;

an inclined tire engaging free;

and an upright back wall;

said wedge being generally right-triangular in profile,

the angle between, said inclined tire engaging face and said base beingbetween about 30 and about 40;

said tire engaging face being provided with tire gripping ribs extendinghorizontally across said face and projecting upwardly therefrom, thesurface of each of said ribs including an area angled downwardly towardsaid back wall;

said base having an opening therein extending longitudinally thereof anddefining with the outer edges of said base a pair of ground grippingrails;

and said base further being concave upwardly for limiting the area ofcontact thereof with the ground.

2. A wheel clock in accordance with claim 1 in which said wedge furtherincludes an internal reinforcing rib extending between said back walland said tire engaging face. I

1. A wheel chock for pneumatic-tired vehicles comprising: a hollow wedgehaving a base; an inclined tire engaging free; and an upright back wall;said wedge being generally right-triangular in profile, the anglebetween said inclined tire engaging face and said base being betweenabout 30* and about 40*; said tire engaging face being provided withTire gripping ribs extending horizontally across said face andprojecting upwardly therefrom, the surface of each of said ribsincluding an area angled downwardly toward said back wall; said basehaving an opening therein extending longitudinally thereof and definingwith the outer edges of said base a pair of ground gripping rails; andsaid base further being concave upwardly for limiting the area ofcontact thereof with the ground.
 2. A wheel clock in accordance withclaim 1 in which said wedge further includes an internal reinforcing ribextending between said back wall and said tire engaging face.